Laserfiche WebLink
California&gional Water Quality Con*--ol Board <br /> \� Central Valley Region <br /> ion <br /> Karl E. Longley,ScD,P.E.,Chair <br /> Linda S.Adams 11020 Sun Center Drive#200,Rancho Cordova,California 95670.6114 Arnold <br /> Secretary for Phone(916)464-3291 •FAX(916)464-4645 Schwarzenegger <br /> Environmental Governor <br /> Protection http://�Iw�ww(�waterboards.ca.gov/cen[ralvalley <br /> 6 August 2009 <br /> AUG 7 2009 <br /> Ms. Vicki Goodenow ENVIRONMENT HEALTH <br /> NuStar Energy L.P. PERMIT/SERVICES <br /> 2330 North Loop 1604 West <br /> San Antonio, TX 78278 <br /> GROUNDWATER MONITORING REPORT SECOND QUARTER 2009, NuSTAR <br /> TERMINALS STOCKTON FACILITY, 2941 NAVY DRIVE, STOCKTON, SAN JOAQUIN <br /> COUNTY <br /> Regional Water Quality Control Board, Central Valley Region (Central Valley Water Board) <br /> staff reviewed the 30 July 2009 Groundwater Monitoring Report, Second Quarter 2009 <br /> (Second QMR) submitted by Ash Creek Associates, Inc. (Ash Creek) on behalf of NuStar <br /> Terminals Operating Partnership L.P. (NuStar) for the NuStar Terminals Stockton Facility <br /> located at 2941 Navy Drive in Stockton (Site). Groundwater monitoring at the Site is conducted <br /> pursuant to Monitoring and Reporting Program (MRP) No. R5-2007-0818. <br /> NuStar and its predecessor have conducted monitoring at the Site since 1992. In 2002, <br /> gasoline releases occurred from aboveground storage tanks (AGTs) G 3301, G 3302, and <br /> D 1503. The principal contaminants of concern (COCs) include total petroleum hydrocarbons <br /> as gasoline (TPHg), TPH as diesel (TPHd), benzene, toluene, ethylbenzene, and xylenes, <br /> methyl tertiary butyl ether (MTBE), and tertiary butyl alcohol. <br /> Groundwater bearing strata underlying the Site have been subdivided into four progressively <br /> deeper units designated zones A through D by NuStar's predecessors and other responsible <br /> parties at neighboring sites. Based on an investigation NuStar conducted during the Fall of <br /> 2008, however, NuStar has designated some of its B-zone wells as C-zone wells. <br /> During the second quarter of 2009, depth to groundwater ranged from about three to 11 feet <br /> below ground surface (bgs). Horizontal gradients were calculated to range from 0.0017 feet <br /> per foot (ft/ft) to 0.006 ft/ft within each zone. Groundwater flow directions were generally to the <br /> southeast in the deep (C and D) zones. Downward vertical gradients prevailed between all the <br /> water bearing zones. The maximum downward gradient was calculated for the ACA-1A and <br /> ACA-1 B well pair at -0.093 ft/ft. Downward vertical gradients historically have been <br /> predominant at this Site. <br /> One source area monitoring well, PS/MW-14, has historically contained separate phase <br /> hydrocarbons (SPH), so it was not usually sampled until August 2005, when SPH was no <br /> longer observed. During the second quarter of 2009, ST-MW/1 contained the highest <br /> concentrations of TPHg at 100,000 micrograms per liter (pg/L), benzene at 17,000 Ng/L, <br /> California Environmental Protection Agency <br /> 0$Recycled Paper <br />